It is important for at least navigational purposes for a moving or movable vehicle to know its position or location. In the case of a ship at sea, there may be situations in which the ship is lost and there are no landmarks in sight. In a battle zone, radio access to Global Positioning System satellites may not be available due to jamming, so that avenue of geolocation is not available.
Improved or alternative arrangements are desired for position and/or velocity determinations.